The outcome of psychopharmacological treatment may depend on genetic polymorphisms of various neurotransmitter systems. We summarize studies of associations between genetic variations with relation to the serotonin system and response to selective serotonin reuptake inhibitors. The results are still preliminary but suggest that treatment response to antidepressant drugs is influenced by genetic factors. They also indicate that the genetic component is polygenic and highly complex and might manifest itself in interaction with other biological and environmental factors. Udgivelsesdato: 2007-Apr-16